Generally there are many things as elements for positively producing bread, but steam venting after the baking may be mentioned as one among them. Namely, when the steam venting after the baking is not effected properly, a dewing phenomenon is caused in the produced bread, so that the bread becomes sticky, or the bread becomes contracted in appearance, thus making it impossible to be baked soft and full.
Accordingly, it may be recognized that steam venting is a compulsory venting operation of the baking chamber interior. FIG. 16 shows a conventional bread producing machine, which has a heating means 1 such as a heater or the like, a baking case 5, which is provided with a mixing, kneading means 4 such as a blade or the like disposed detachably within a baking chamber 3 which is adapted to opened and closed at the upper portion by a cover 2. An air inlet route 6 is disposed to introduce air into the baking chamber 3 which also has a hole-shaped exhaust route 7 formed in the cover 2. In the ventilation within the baking chamber 3, the air is force to fed into the baking chamber 3 by the driving operation of a fan 8 disposed in the air inlet route 6, so that the steam is discharged from the exhaust route 7.
In the bread producing machine up to this time, a so-called forced type of ventilation is provided by the fan 8 disposed in the air inlet route 6 to force the air into the baking chamber 3 so that there is bound to become a positive pressure zone within the baking chamber 3. But the steam exists even in the gap between the bread periphery and the baking case 5, in addition to the upper surface of the bread. It is generally known that the gap is formed in the baking step.
However, in the conventional forced type, there are no problems in particular in terms of the steam exhaust on the top surface of the bread, but the steam existing in the gap between the bread periphery and the baking case 5 is depressed inversely and is prevented from being discharged as the baking chamber 3 becomes a positive pressure zone as described hereinabove. Accordingly, in the conventional construction, dewing was caused especially in the peripheral face of the bread to prevent the expected object from being achieved.